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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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336                                ALASKAN GLACIER STUDIES
cascading ice tongues, like Roaring Glacier, for it slopes at an angle of only about 12°. It ends 100 feet or less above the level of the fiord, from which it is separated by an out-wash gravel fan, and by a morainic area with many small ponds. There was practically no change in this glacier from 1899 to 1910, but in former times it evidently expanded and formed a bulb glacier, and still earlier was tributary to Harriman Glacier.
Roaring Glacier. Roaring Glacier, three-fourths of a mile north of Harriman Glacier, on the northwestern side of the fiord, is spoken of by Gilbert as an ice tongue which "owes the peculiarity suggesting its name to an abrupt change of grade. From a comparatively gentle slope it passes to one so steep that loose masses find no lodgment, and AS its movement steadily projects its end beyond the point of inflection, fragments of ice break away and tumble down the steep incline, to gather in a heap far below, where they lie until melted."
It seems to have been less active in 1905 than in 1899, for a photograph by Grant and Paige shows that in 1905 there was no heap of ice fragments below the glacier, but that, as in the case of Baker Glacier in the same year, there was an extensive area of bare rock below the terminus.
Roaring Glacier became more active between 1905 and 1910 for the barren zone, which was free from snow in August, 1905, was partly covered in August, 1910, by an extensive snow and ice block fan, similar to that of Baker Glacier. This fan could only have been formed by an increase in activity of the glacier with accompanying sliding down of many ice blocks from the terminus, which is 700 to 1000 feet above the fiord. Advance seemed to be still going on in August, 1910.
Roaring Glacier has evidently descended to fiord level since it became independent of Haniman Glacier, for around the borders of the snow fan there is a crescentic terminal moraine, the outer part of which is covered with shrubs. It extends down to the fiord, where it makes a small cape; and since it rises steeply from the water's edge, it is evident that the glacier reached tidewater when last expanded. The crescentic character of this •deposit shows that it was not built by Harriman Glacier, but the knobby morainic topography does not absolutely preclude the possibility of its having been built by an avalanche rather than by a bulb-shaped extension of Roaring Glacier, though we do not t.Tn'TiTr this avalanche origin likely.
Wedge Glacier. Wedge Glacier lies on the eastern side of the fiord, opposite Roaring Glacier (Fig. 50). Its general shape is indicated by its name, forming a striking contrast with ice tongues, like Dirty Glacier, that have bulb or fan-like termini. Wedge Glacier •ends in a narrow valley a few hundred feet above the fiord, and except in detached spots was covered with snow clear to the end in August, 1910.
Smaller Glaciers. Two unnamed ice tongues north of Wedge Glacier have snowfields "which coalesce with that of Toboggan Glacier and terminate £ and £ of a mile re-.spectively from the fiord. Three small ice tongues on the western side of the fiord between Roaring and Cataract Glaciers, together with Roaring Glacier, two glaciers in hanging valleys above the northwestern end of Harriman Glacier, and several others, fall in a •class described by Gilbert. He says, they "occupy elevated valleys far above the main trough, and these upland valleys probably constitute a system initiated at an earlier epoch, when the fiord was flooded with ice to a greater depth. . . . No measurements were made, but it is evident from an inspection of photographs that the heights of such features in this neighborhood are approximately the same as in the vicinity of